Advertisement detection system and method based on fingerprints

ABSTRACT

The present invention relates to an advertisement detection system based on fingerprints, and provides an advertisement detection systems based on fingerprints, including a content stream storage unit for storing broadcast content in real time, a section selection unit for selecting a reference section and a test section from broadcast content stored by the content stream storage unit, a fingerprint extraction unit for extracting fingerprints from the reference section and the test section selected by the section selection unit using one or more methods, a fingerprint matching unit for comparing the fingerprints from the test section and the reference section, extracted by the fingerprint extraction unit, with each other and then performing matching between the fingerprints, an advertisement section determination unit for determining advertisement segments from the test section based on results of the matching performed by the fingerprint matching.

RELATED DISCLOSURES

This is a continuation of U.S. patent application Ser. No. 15/228,243,filed Aug. 4, 2016, which is a continuation of U.S. patent applicationSer. No. 14/122,674, filed Nov. 26, 2013, which is a national phaseentry of, and claims priority to, International Patent Application No.PCT/KR2013/005805 filed Jul. 1, 2013.

TECHNICAL FIELD

The present invention relates, in general, to an advertisement detectionsystem and method and, more particularly, to a system and method thatcan detect advertisements contained in broadcast content based onfingerprints.

BACKGROUND ART

Television (TV) broadcast content may be divided into a TV programsection and an advertisement section. Generally, an advertisementsection is recognized as a section having low importance or as anunnecessary section from the standpoint of viewers, so that researchinto technology for automatically detecting such an advertisementsection and eliminating the detected advertisement section orreprocessing the detected advertisement section in another form, andthen providing the TV content to users has been widely conducted.

Meanwhile, the necessity to run a related business for TV advertisementsor to continuously monitor the advertisements of competitors is alsopresent. Therefore, if a program section and an advertisement sectioncan be automatically distinguished from each other regardless of whetherthe program section or the advertisement section is important, greatconvenience may be provided.

However, distinguishing between a program section and an advertisementsection in broadcast content was manually performed by a person in mostcases in the past, and research into technology for automaticallydistinguishing between a program section and an advertisement sectionhas been conducted, but there is the limitation that efficiency is stillvery low.

Conventional known methods of detecting an advertisement sectioninclude, for example, a method of detecting an advertisement section bydetecting black frames because there are many cases where black framesare inserted into start and end time points of advertisements.

Alternatively, as described in the following Prior Art Document 2, amethod of utilizing a principle by which audio signals are not presentat time points at which advertisements are changed is also known.

Further, a method of utilizing a principle by which the lengths ofadvertisements are as uniform as 15 seconds or 30 seconds, or aprinciple by which the same advertisement repeatedly appears in abroadcast, or a method of detecting a broadcast logo continuouslyappearing in a TV program section, has also been used, and variousmethods mentioned above have also been combined to detect anadvertisement section.

However, since there are many cases where the signal characteristics ofadvertisement sections are different for respective countries andbroadcasting channels, it is difficult to solve all differences usingthe above-mentioned conventional methods. For example, in the U.S.,there are many cases where black frames are inserted into the start andend positions of advertisements, but this is not the case in othercountries.

Further, existing advertisements are arranged into a database (DB) whichmay be occasionally used to detect an advertisement section, but thereis a limitation in that it is very difficult to previously construct aDB storing all advertisements.

Meanwhile, Korean Patent Application Publication No. 10-2011-0129325(Date of Publication: Dec. 1, 2011) relates to an “Advertisement imagedetection method and apparatus” and discloses an advertisement imagedetection method including the step of partitioning each of a pluralityof frames of a monitoring target image, in which broadcast content andan advertisement image played by a video play device are mixed, intosub-blocks having a predetermined size; the step of calculating piecesof feature information of respective sub-blocks corresponding to presetlocations among the sub-blocks having the predetermined size; the stepof converting the pieces of feature information into feature informationvectors; and the step of comparing the feature information vectors withthe feature information vectors of a reference advertisement imagedesired to be detected and previously stored in a DB and detecting thereference advertisement image.

However, this technology has a limitation in that pieces of featureinformation about advertisement images must be previously and accuratelystored, and the technology can be applied only to a case where thepieces of feature information of a monitoring target image and anadvertisement image are completely identical to each other, and cannotbe applied to a case where advertisement sections are only partiallyidentical. Furthermore, this technology is fundamentally limited in thata DB is fixed and then the DB cannot be dynamically updated with thelapse of time.

PRIOR ART DOCUMENTS

-   1. Korean Patent Application Publication No. 10-2011-0129325 (Date    of Publication: Dec. 1, 2011)-   2. D. A. Sadlier et al., “Automatic TV advertisement detection from    mpeg bitstream,” Journal of the Patt. Rec. Society, vol. 35, no. 12,    pp. 215, December 2002.

DISCLOSURE Technical Problem

The present invention has been made keeping in mind the above problems,and an object of the present invention is to provide an advertisementdetection system and method, which can accurately and effectively detectadvertisement sections by repeating a procedure for detectingadvertisement sections continuously appearing in broadcast content andarranging the advertisement sections into a DB.

Another object of the present invention is to provide a system andmethod, which can continuously store broadcast content in real time,select a reference section and a test section from the stored broadcastcontent, detect advertisement sections, and change the reference sectionand the test section based on the results of the detection, thusefficiently selecting the comparison target section of broadcast contentthat is continuously received, and dynamically coping with the broadcastcontent.

A further object of the present invention is to provide a system andmethod, which can more accurately and effectively detect advertisementsby detecting repeated advertisement sections based on fingerprints,partitioning each detected advertisement section into segments, storingthe segments in a DB, and dividing each stored segment into sub-dividedadvertisement sections.

Technical Solution

In order to accomplish the above objects, the present invention providesan advertisement detection system based on fingerprints, including acontent stream storage unit for storing broadcast content in real time;a section selection unit for selecting a reference section and a testsection from broadcast content stored by the content stream storageunit; a fingerprint extraction unit for extracting fingerprints from thereference section and the test section selected by the section selectionunit using one or more methods; a fingerprint matching unit forcomparing the fingerprints from the test section and the referencesection, extracted by the fingerprint extraction unit, with each otherand then performing matching between the fingerprints; an advertisementsection determination unit for determining advertisement segments fromthe test section based on results of the matching performed by thefingerprint matching unit; an advertisement DB management unit forstoring segment information about the advertisement segments determinedby the advertisement section determination unit in an advertisementdatabase (DB) and managing the advertisement DB; and a section updateunit for changing the reference section and the test section selected bythe section selection unit.

In this case, the section partitioning unit may select a predeterminedtime section, ranging from a most recent storage time point, as the testsection from the broadcast content stored by the content stream storageunit, and select a predetermined time section, ranging from an end pointof the test section, as the reference section.

Further, the test section may have a time length shorter than that ofthe reference section.

Furthermore, the fingerprint extraction unit may partition each of thereference section and the test section into unit sections having apreset time length and extract a fingerprint from each unit sectionusing any one of fingerprint extraction methods, and the fingerprintmatching unit may perform a procedure for comparing a fingerprint,extracted from each unit section of the test section, with fingerprints,extracted from all unit sections of the reference section, on all unitsections of the test section, thus performing matching betweenfingerprints.

Furthermore, start points of the unit sections are spaced apart fromeach other by a time length (S).

Preferably, the time length (S) between the start points of the unitsections may be shorter than the time length of each unit section.

Furthermore, the advertisement section determination unit determinescontinuous unit sections of the test section, which match unit sectionsof the reference section, to be the advertisement segments based on theresults of the matching performed by the fingerprint matching unit.

Furthermore, the fingerprint extraction unit may respectively partitioneach advertisement segment and a section corresponding to theadvertisement segment in the reference section into unit sections havinga preset time length, and extract fingerprints from the respective unitsections using one or more methods other than the method of extractingfingerprints from the reference section and the test section, and thefingerprint matching unit may perform a procedure for comparing afingerprint extracted from each unit section of the advertisementsegment with fingerprints extracted from all unit sections correspondingto the advertisement segment in the reference section, on all unitsections of the advertisement segment, thus performing fingerprintmatching.

Furthermore, the advertisement section determination unit may finallydetermine continuous unit sections of the advertisement segment, whichmatch unit sections corresponding to the advertisement segment in thereference section, to be the advertisement segments based on the resultsof the matching performed by the fingerprint matching unit.

Furthermore, the advertisement section determination unit may comparefingerprints of the advertisement segments with fingerprints ofadvertisement segments previously registered in the advertisement DB,and finally determine the advertisement segments.

Furthermore, the fingerprints may be extracted using one or more methodsother than a method of extracting fingerprints from the referencesection and the test section.

Furthermore, the advertisement DB management unit may store one or morefingerprints from the advertisement segments determined by theadvertisement section determination unit and pieces of time informationabout the advertisement segments as segment information in theadvertisement DB.

Furthermore, the section update unit may change the reference section bycausing an interval ranging to an end point of each advertisementsegment determined from the test section to be included in the referencesection.

Furthermore, when there are a plurality of advertisement segments, thereference section may be changed by causing an interval ranging to anend point of a last advertisement segment to be included in thereference section.

Furthermore, an overall length of the reference section may be uniformlymaintained by changing a position of a start point of the referencesection by a length newly included in the reference section.

Furthermore, the section update unit may extend a length of the testsection by a length by which the position of the start point of thereference section is changed.

Furthermore, the section update unit may change the reference section bycausing an interval ranging to a position previous to a start point ofeach advertisement segment determined from the test section to beincluded in the reference section.

Furthermore, when there are a plurality of advertisement segments, thereference section is changed by causing an interval ranging to aposition previous to a start point of an initial advertisement segmentto be included in the reference section.

Furthermore, an overall length of the reference section may be uniformlymaintained by changing a position of a start point of the referencesection by a length newly included in the reference section.

Furthermore, the section update unit may be configured to store piecesof time information about start points of reference sectionscorresponding to the advertisement segments determined by theadvertisement section determination unit in advertisement segmenthistory, and be configured to, whenever a predetermined period of timehas elapsed, check a preset search section for the advertisement segmenthistory, and remove sections corresponding to a time point previous to aminimum value of pieces of time information included in the searchsection from the reference section.

Furthermore, the advertisement DB management unit may select two ofadvertisement segments stored in the advertisement DB, comparefingerprints of the selected advertisement segments with each other,detects an identical section, and separates the identical section andremaining sections of the selected advertisement segments, thusperforming a new advertisement segment formation procedure.

Furthermore, advertisement segments, existing before separation isperformed, may be removed from the advertisement DB.

Furthermore, the new advertisement segment formation procedure may berepeatedly performed on any two advertisement segments a preset numberof times (N).

Furthermore, the new advertisement segment formation procedure may beperformed on two segments, time lengths of which are equal to or greaterthan a predetermined time length (K).

Furthermore, the new advertisement segment formation procedure may berepeatedly performed until advertisement segments having an identicalsection are not present any longer in any advertisement segmentsincluded in the advertisement DB.

Furthermore, the advertisement DB management unit may updatefingerprints and time information of the newly formed advertisementsegments.

In accordance with another aspect of the present invention, there can beprovided as an advertisement detection method based on fingerprints,including a first step of storing broadcast content in real time; asecond step of selecting a reference section and a test section from thestored broadcast content; a third step of extracting fingerprints fromthe reference section and the test section using one or more methods; afourth step of comparing fingerprints extracted from the test sectionwith fingerprints extracted from the reference section and thenperforming matching between fingerprints; a fifth step of determiningadvertisement segments from the test section based on results of thematching; a sixth step of storing segment information about thedetermined advertisement segments in an advertisement database (DB); anda seventh step of changing the reference section and the test section.

Advantageous Effects

In accordance with the present invention, there can be provided anadvertisement detection system and method, which can accurately andeffectively detect advertisement sections by repeating a procedure fordetecting advertisement sections continuously appearing in broadcastcontent and arranging the advertisement sections into a DB.

Further, the present invention is advantageous in that it can provide asystem and method, which can continuously store broadcast content inreal time, select a reference section and a test section from the storedbroadcast content, detect advertisement sections, and change thereference section and the test section based on the results of thedetection, thus efficiently selecting the comparison target section ofbroadcast content that is continuously received, and dynamically copingwith the broadcast content.

Furthermore, the present invention can provide a system and method,which can more accurately and effectively detect advertisements bydetecting repeated advertisement sections based on fingerprints,partitioning each detected advertisement section into segments, storingthe segments in a DB, and dividing each stored segment into sub-dividedadvertisement sections.

DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram showing the overall configuration of anadvertisement detection system 100 based on fingerprints according to anembodiment of the present invention;

FIG. 2 is a diagram showing an example of a method of selecting areference section and a test section using a section selection unit 20;

FIG. 3 is a diagram showing the operation of a fingerprint extractionunit 30 and a fingerprint matching unit 40;

FIG. 4 is a diagram showing a procedure for determining advertisementsegments from a test section 22;

FIG. 5 is a diagram showing an example of segment information stored inan advertisement database 80;

FIG. 6 is a diagram showing an example of a method of changing areference section using a section update unit 70;

FIG. 7 is a diagram showing a procedure for partitioning anadvertisement segment into advertisement segments which are smallerunits and forming new advertisement segments using an advertisement DBmanagement unit 60;

FIGS. 8 and 9 are diagrams showing a procedure for partitioningadvertisement segments; and

FIG. 10 is a diagram showing an embodiment of an advertisement detectionmethod according to the present invention.

BEST MODE

Hereinafter, embodiments of the present invention will be described indetail with reference to the attached drawings.

FIG. 1 is a diagram showing the overall configuration of anadvertisement detection system 100 based on fingerprints according to anembodiment of the present invention.

Referring to FIG. 1, the advertisement detection system 100 based onfingerprints (hereinafter referred to as “advertisement detection system100”) according to the present embodiment includes a content streamstorage unit 10, a section selection unit 20, a fingerprint extractionunit 30, a fingerprint matching unit 40, an advertisement sectiondetermination unit 50, an advertisement database (DB) management unit60, a section update unit 70, and an advertisement DB 80.

The content stream storage unit 10 functions to store broadcast contentin real time. The broadcast content may be content provided via, forexample, TV terrestrial broadcasting or cable television. The contentstream storage unit 10 may store such broadcast content in real time orcontinuously.

The section selection unit 20 performs the function of selecting areference section and a test section from the broadcast content storedby the content stream storage unit 10.

The test section is a section required to identify whether anadvertisement is contained, and the reference section is a section thatis a comparison target making it possible to identify whether anadvertisement is contained in the test section.

The section selection unit 20 may select, as the test section, apredetermined time section ranging from the most recent storage timepoint from the broadcast content stored by the content stream storageunit 10, and may select, as the reference section, a predetermined timesection ranging from the end point of the test section.

FIG. 2 is a diagram showing an example of a method of selecting areference section and a test section using the section selection unit20.

As shown in FIG. 2, if it is assumed that, based on the time of storedbroadcast content, the rightmost position is the most recent time pointt₀, an interval ranging from the rightmost time point, that is, the mostrecent storage time point t₀, to time point t₁ by a predetermined timelength N, may be selected as the test section 22. Further, an intervalranging from the end point t₁ of the test section 22 to time point t₂ bya predetermined time length L may be selected as the reference section21.

In this case, it is preferable that the time length of the test section22 be shorter than that of the reference section 21, in other words, thetime length of the reference section 21 be longer than that of the testsection 21. The reason for this is that the detection of anadvertisement contained in the test section 22 is performed to havehigher discrimination as the reference section 21 becomes longer. Forexample, a section having a length of 10 hours may be selected as thetest section 22, and a section having a length of three days may beselected as the reference section 21.

Referring back to FIG. 1, the fingerprint extraction unit 30 functionsto extract fingerprints from the reference section and the test sectionselected by the section selection unit 20 using one or more methods, andthe fingerprint matching unit 40 performs matching between fingerprintsby comparing the fingerprints extracted from the test section by thefingerprint extraction unit 30 with the fingerprints extracted from thereference section. Meanwhile, the advertisement section determinationunit 50 functions to determine advertisement segments from the testsection based on the results of the matching performed by thefingerprint matching unit 40.

That is, the fingerprint extraction unit 30 partitions each of thereference section and the test section into unit sections having apreset time length, and extracts a fingerprint from each unit sectionusing any one of fingerprint extraction methods. The fingerprintmatching unit 40 performs matching between fingerprints by performing aprocedure for comparing a fingerprint extracted from each unit sectionof the test section with fingerprints extracted from all unit sectionsof the reference section, on all unit sections of the test section.Further, the advertisement section determination unit 50 determinesadvertisement segments from the test section based on the results of thematching.

FIG. 3 is a diagram showing the operation of the fingerprint extractionunit 30 and the fingerprint matching unit 40.

As shown in FIG. 3, in the test section 22, a unit section ranging fromtime point t₁ by a preset time length is generated. Further, even in thereference section 21, a unit section ranging from time point t₂ by atime length corresponding to that of the unit section of the testsection 22 is generated. The fingerprint extraction unit 30 extractsfingerprints from the two unit sections, and the fingerprint matchingunit 40 performs matching between the extracted fingerprints.

The fingerprint matching unit 40 temporarily stores the results of thematching, for example, a matching score, generates a subsequent unitsection of the reference section 21, and then performs matching betweenfingerprints. In this case, the start point of the subsequent unitsection is preferably spaced apart from the start point of thepreviously generated unit section by a movement length S shorter thanthe time length of the unit section on a time axis. That is, individualunit sections preferably have overlapping portions with each other onthe time axis.

When this procedure is performed on all sections to the end point t₁ ofthe reference section 21, matching between fingerprints for one unitsection generated in the test section 22 is completed.

If the extraction and matching of fingerprints from all unit sections ofthe reference section 21 have been completed on the first unit sectionof the test section 22, a subsequent unit section of the test section 22is generated, and the above procedure is repeated. In this case, thestart point of the subsequent unit section of the test section 22 isalso preferably spaced apart from the start point of the previous unitsection by a time length shorter than the time length of the unitsection.

The interval between the start points of the unit sections of the testsection 22 and the interval between the start points of the unitsections of the reference section 21 may be identical to or differentfrom each other.

If this procedure has been repeatedly performed even on the last unitsection of the test section 22, the results of the matching offingerprints of the reference section 21 with the fingerprints of therespective unit sections of the test section 22 may be obtained. Theadvertisement section determination unit 50 determines whether matchinghas been performed based on the results of the matching of fingerprintswith the respective unit sections, that is, a fingerprint matchingscore, determines continuous sections in matched unit sections, anddetermines the continuous unit sections to be advertisement segments.

FIG. 4 is a diagram showing a procedure for determining advertisementsegments from the test section 22.

In the test section 22 on the right side of FIG. 4, portions indicatedin blue indicate continuous sections in which matching of fingerprintswith the reference section 21 is achieved, and it can be seen that twocontinuous sections t_(a)˜t_(b) and t_(c)˜t_(d) are determined to beadvertisement segments.

Meanwhile, in the present invention, a fingerprint denotes feature dataindicative of the features of data, such as audio data, image data, orvideo data, and is also called fingerprint data, deoxyribonucleic acid(DNA) data, or gene data. Technology for extracting and comparing suchfingerprints, various methods are proposed according to the conventionaltechnology. If such fingerprints are utilized, the identicalness of datamay be easily determined, and then fingerprints have recently beenwidely used in Digital Rights Management (DRM) fields or the like.

For example, in the case of audio data, fingerprints may be generatedusing various types of feature data (e.g., frequency, amplitude, etc.)indicative of the features of audio data, and in the case of image orvideo data, fingerprints may be generated using various types of featuredata related to image or video data (e.g., the motion vectorinformation, color information, etc. of each frame).

An object of the present invention is not a method itself of extracting(generating) such fingerprint data, and any type of conventionalfingerprint generation/extraction method can be used without change, andthus a detailed description thereof will be omitted here.

According to Korean Patent Application No. 10-2007-0044251 (entitled“Method and apparatus for generating audio fingerprint data and methodand apparatus for comparing audio data using the same”), Korean PatentApplication No. 10-2007-0054601 (entitled “Method and apparatus fordetermining identicalness of video data and detecting an identicalsection”), Korean Patent Application No. 10-2007-0060978 (entitled“Method and system for clustering pieces of video data havingidenticalness among pieces of video data”), Korean Patent ApplicationNo. 10-2007-0071633 (entitled “Method and apparatus for providing avideo data search service using video data clusters”), Korean PatentApplication No. 10-2007-0091587 (entitled “Method and apparatus forsetting and providing advertisement data using video data clusters”),and Korean Patent Application No. 10-2008-0051688 (entitled “Videoprocessing method and apparatus”), which are filed by the presentapplicant, methods of generating fingerprints of audio, image or videodata and comparing pieces of data using such fingerprints are described,and it is apparent that the fingerprint extraction methods by thepresent applicant may also be used in the present invention. In summary,the present invention may use fingerprint extraction technology known tothe prior art without change, regardless of which type of fingerprintextraction method is to be used.

In this way, methods of extracting fingerprints may be implemented usingvarious methods. As described above, the present invention may also beconfigured such that, if advertisement segments have been determined bythe advertisement section determination unit 50, fingerprints areextracted from the advertisement segments using another fingerprintextraction method and then secondary matching is performed by comparingthe extracted fingerprints with those of the reference section.

That is, with respect to each advertisement segment determined by theadvertisement section determination unit 50, the fingerprint extractionunit 30 may respectively partition the advertisement segment and asection corresponding to the advertisement segment in the referencesection into unit sections having a preset time length, and extractfingerprints from the respective unit sections using one or more methodsother than the method of extracting fingerprints from the referencesection and the test section. Further, the fingerprint matching unit 40may perform fingerprint matching by performing a procedure for comparinga fingerprint extracted from each unit section of the advertisementsegment with fingerprints extracted from all unit sections correspondingto the advertisement segment in the reference section on all unitsections of the advertisement segment.

After this procedure has been performed, the advertisement sectiondetermination unit 50 may finally determine the continuous unit sectionsof the advertisement segment, which match the unit sectionscorresponding to the advertisement segment in the reference section, asthe advertisement segment, based on the results of the matchingperformed by the fingerprint matching unit 40.

Meanwhile, the advertisement section determination unit 50 may also beconfigured to compare the fingerprints of the section determined to bethe advertisement segment with the fingerprints of advertisementsegments previously registered in the advertisement DB 80, and tofinally determine the corresponding advertisement segment as theadvertisement segment when the fingerprints match each other.Preferably, the fingerprints at this time may be fingerprints obtainedusing one or more methods other than the method of extractingfingerprints from the reference section and the test section in theabove procedure.

Referring back to FIG. 1, the advertisement DB management unit 60 andthe section update unit 70 will be described below.

The advertisement DB management unit 60 functions to store segmentinformation about the advertisement segments determined by theadvertisement section determination unit in the advertisement DB 80 andmanage the advertisement DB 80.

FIG. 5 is a diagram showing an example of segment information stored inthe advertisement DB 80.

Referring to FIG. 5, segment information includes a segment identifier,section start point time information, a section length, and afingerprint.

The segment identifier denotes an identifier (ID) uniquely assigned toeach advertisement segment so that the advertisement segment can beidentified, and the section start point time information may be storedin the form of, for example, 11:59:35 on May 20, 2013(2013-05-20/11:59:35). The section length denotes the overall sectionlength of the advertisement segment and may be stored in the form of,for example, 30 seconds or 20 seconds.

The fingerprint denotes a fingerprint extracted by the fingerprintextraction unit 30, as described above. As described above, fingerprintextraction methods in the present invention may be implemented usingvarious types of methods, and thus fingerprints stored in segmentinformation may also be fingerprints based on respective methods, whichare extracted using various types of methods.

The section update unit 70 functions to change the reference section andthe test section selected by the section selection unit 20.

The section update unit 70 may change the reference section so that theadvertisement segment determined from the test section by theadvertisement section determination unit 50 is included in the referencesection, in other words, so that an interval ranging to the end point ofthe advertisement segment determined from the test section is includedin the reference section. For example, as shown in FIG. 4, the referencesection may be changed such that an interval ranging to the end pointt_(b) of the advertisement segment having a time section t_(a)˜t_(b),that is, an interval t₁˜t_(b), is included in the reference section.

Meanwhile, when there are a plurality of advertisement segments, thereference section may be changed so that an interval ranging to the endpoint of the last advertisement segment (in the case of FIG. 4, timet_(d)) is included in the reference section.

When the reference section is changed in this way, the overall length ofthe reference section may be uniformly maintained by changing theposition of the start point of the reference section by a length newlyincluded in the reference section. For example, as shown in FIG. 4,since the reference section has a length corresponding to time length L,the overall time length of the reference section may be uniformlymaintained at L by removing part of the reference section by an intervalt₁˜t_(d) from time t₂ to the right when the interval t₁˜t_(d) is newlyincluded in the reference section.

In this manner, when the position of the start point of the referencesection is changed, the start point of the test section is shifted inproportion to such a change, and thus the end point of the test sectionmay be shifted by the length by which the position of the start point ofthe reference section is changed.

When the test section and the reference section are changed by thesection update unit 70 in this manner, the procedure for matchingfingerprints between the test section and the reference section anddetermining an advertisement section via the fingerprint extraction unit30, the fingerprint matching unit 40, and the advertisement sectiondetermination unit 50 may be repeated.

Meanwhile, the section update unit 70 may also change a referencesection using a method shown in FIG. 6. FIG. 6 is a diagram showing anexample in which the section update unit 70 changes a reference section.

The section update unit 70 stores pieces of time information about thestart points of reference segments corresponding to the advertisementsegments determined by the advertisement section determination unit 50in advertisement segment history 7 sequentially from above whenever theadvertisement segment is determined, as shown in FIG. 6. Whenever apredetermined period of time has elapsed, the section update unit 70determines a minimum value from among pieces of time information storedin the search section for the advertisement segment history having apreset length W from the bottom of the advertisement segment history,that is, the most recent storage time information, and may removesections corresponding to time points previous to the minimum value fromthe reference sections. The reason for this is that the sectionscorresponding to the time points previous to the minimum valuecorrespond to reference sections in which advertisements scarcely occurfor a predetermined period of time, and then these reference sectionsare intended to be removed from reference sections.

Meanwhile, if the advertisement segments are determined via theabove-described procedure, and pieces of segment information about theadvertisement segments are stored in the advertisement DB 80, as shownin FIG. 5, the advertisement DB management unit 60 may partition eachstored advertisement segment into advertisement segments which aresmaller units. The reason for this is that, for example, even in thecase of advertisements for the same product, pieces of time informationmay be configured to be differently set and edited.

FIG. 7 is a diagram showing a procedure in which the advertisement DBmanagement unit 60 partitions an advertisement segment intoadvertisement segments which are smaller units and generates newadvertisement segments.

Referring to FIG. 7, it is assumed that K advertisement segments arepresent, advertisement segment 1 is composed of [A][B][Z], advertisementsegment 2 is composed of [A][B][C], and advertisement segment K iscomposed of [B][C][A][R]. Here, the same letter denotes the samesection.

In this state, any two of advertisement segments are selected,fingerprints of the selected advertisement segments are compared witheach other, and the same sections are detected. Thereafter, the samesections and the remaining sections of the selected advertisementsegments are separated, and then new advertisement segments may beformed.

For example, when the advertisement segment 1 composed of [A][B][Z] andthe advertisement segment 2 composed of [A][B][C] are compared with eachother, the same sections [A] [B] may be detected, and new advertisementsegments may be formed by separating the detected same sections and theremaining sections ([Z], [C]). If two of the advertisement segments areselected and the above procedure is repeatedly performed on the selectedadvertisement segments, new advertisement segments shown as ‘primary newadvertisement segments’ in FIG. 7 may be formed. Next, if the sameprocedure is also repeatedly performed on the new advertisementsegments, the final new advertisement segments may be formed, as shownin FIG. 7.

FIGS. 8 and 9 are diagrams showing a procedure for partitioningadvertisement segments.

FIG. 8 is a diagram showing a procedure for comparing the advertisementsegments 1 and 2 of FIG. 7 with each other and detecting the samesection. As shown in FIG. 8, the same sections are [A][B], which may bedetected using a procedure for extracting and comparing fingerprints, asdescribed above in FIGS. 1 to 6.

Once the same sections have been detected, if the same sections and theremaining sections, that is, non-identical sections, are separated fromthe original advertisement segments 1 and 2, new advertisement segmentsrespectively implemented using [A][B], [Z], and [C] are formed, as shownon the right side of FIG. 8.

The advertisement segments existing before separation, that is, theadvertisement segments 1 and 2, are removed from the advertisement DB asthe new advertisement segments are formed.

FIG. 9 is a diagram showing a procedure for comparing the advertisementsegment K of FIG. 7 with the advertisement segment implemented using [C]of the new advertisement segments, newly generated in FIG. 8, with eachother, and detecting the same section. Referring to FIG. 9, if the samesection is [C] and is separated, it can be seen that two newadvertisement segments respectively implemented using [A][R] on theright side and [B] on the left side may be formed. Thereafter, theexisting advertisement segment K is removed from the advertisement DB80.

When this procedure is repeatedly performed on advertisement segmentsstored in the advertisement DB 80, the final new advertisement segmentsmay be obtained, as shown in FIG. 7.

In this case, the procedure for forming new advertisement segments maybe repeatedly performed on any two advertisement segments a presetnumber of times (N).

Further, this procedure may be performed only on two segments, the timelengths of which are equal to or greater than a predetermined timelength K.

Furthermore, the procedure for forming new advertisement segments may berepeatedly performed until advertisement segments having the samesection are not present any longer in any advertisement segmentsincluded in the advertisement DB.

Meanwhile, if new advertisement segments are finally formed via theabove-described procedure, the advertisement DB management unit 70updates segment information about the new advertisement segments, thatis, fingerprints and time information (see FIG. 5) in correspondencewith the new advertisement segments.

FIG. 10 is a diagram showing an embodiment of an advertisement detectionmethod performed by the advertisement detection system 100 describedwith reference to FIGS. 1 to 9.

First, the content stream storage unit 10 stores broadcast content inreal time (S100), and the section selection unit 20 selects a referencesection and a test section from the broadcast content stored by thecontent stream storage unit 10 (S110).

The fingerprint extraction unit 30 extracts fingerprints from thereference section and the test section selected by the section selectionunit 20 using one or more methods (S120), and the fingerprint matchingunit 40 compares the fingerprint extracted from the test section by thefingerprint extraction unit 30 with the fingerprint extracted from thereference section and performs matching between the fingerprints (S130).

The advertisement section determination unit 50 determines advertisementsegments from the test section based on the results of the matching bythe fingerprint matching unit 40 (S140), and the advertisement DBmanagement unit 60 stores the segment information about theadvertisement segments determined by the advertisement sectiondetermination unit 50 in the advertisement DB 80 (S150).

Next, either at regular intervals or when a predetermined conditionoccurs, the section update unit 70 changes the reference section and thetest section selected by the section selection unit 20 (S160).

Although the preferred embodiments of the present invention have beendisclosed with reference to the preferred embodiments, those skilled inthe art will appreciate that the present invention is not limited to theabove embodiments and various changes and modifications are possible.

The invention claimed is:
 1. A method for advertisement detection basedon fingerprints, the method comprising: storing a sequence of broadcastcontent in real time; selecting a reference section and a test sectionfrom the stored sequence of broadcast content, wherein the selected testsection and the selected reference section are respective time sectionsdefined in relation to each other in the stored sequence of broadcastcontent, and wherein selecting the reference section and the testsection from the stored sequence of broadcast content comprisesselecting from the stored sequence of broadcast content a first timesection as the test section and selecting from the same stored sequenceof broadcast content a second time section, ranging from an end point ofthe test section, as the reference section; extracting fingerprintsrespectively from the selected reference section and from the selectedtest section, using one or more fingerprint extraction methods;comparing the extracted fingerprints from the test section with theextracted fingerprints from the reference section to perform matchingbetween the compared fingerprints; determining advertisement segmentsfrom the test section based on results of the matching; and storingsegment information about the determined advertisement segments in anadvertisement database.
 2. The method of claim 1, wherein selecting thefirst time section as the test section comprises selecting as the firsttime section a time section ranging from a most recent storage point ofthe stored sequence of broadcast content.
 3. The method of claim 1,wherein extracting fingerprints respectively from the selected referencesection and from the selected test section comprises partitioning eachof the reference section and the test section into unit sections havinga preset time length, and extracting a fingerprint from each unitsection using a fingerprint extraction method, and wherein comparing theextracted fingerprints from the test section with the extractedfingerprints from the reference section comprises, for each unit sectionof the test section, comparing a fingerprint extracted from the unitsection of the test section with fingerprints extracted from all unitsections of the reference section.
 4. The method claim 3, wherein startpoints of the unit sections are spaced apart from each other by a firsttime length, and wherein the first time length between the start pointsof the unit sections is shorter than the preset time length of each unitsection.
 5. The method of claim 3, wherein determining advertisementsegments from the test section based on results of the comparingcomprises determining advertisement segments as continuous unit sectionsof the test section that match unit sections of the reference section.6. The method of claim 1, wherein storing segment information about thedetermined advertisement segments in an advertisement database comprisesstoring in the advertisement database (i) one or more fingerprints fromthe determined advertisement segments and (ii) pieces of timeinformation about the advertisement segments.
 7. The method of claim 1,wherein the selected test section is a more recent time segment than theselected reference section in the sequence of content.
 8. The method ofclaim 1, further comprising: for each advertisement segment, (a)partitioning into respective unit sections having a preset time lengthboth the advertisement segment and a section corresponding to theadvertisement segment in the reference section, and extractingfingerprints from the respective unit sections, (b) for each respectiveunit section of the advertisement segment, comparing a fingerprintextracted from the respective unit section with fingerprints extractedfrom all respective unit sections corresponding to the advertisementsegment in the reference section, and (c) determining continuousrespective unit sections of the advertisement segment that matchrespective unit sections corresponding to the advertisement segment inthe reference section, to be the advertisement segment.
 9. The method ofclaim 1, wherein storing segment information about the determinedadvertisement segments in an advertisement database comprises storingpieces of time information about start points of reference sectionscorresponding to the determined advertisement segments in advertisementsegment history.
 10. A method for advertisement detection based onfingerprints, the method comprising: storing a sequence of broadcastcontent in real time; selecting a reference section and a test sectionfrom the stored sequence of broadcast content, wherein the selected testsection and the selected reference section are respective time sectionsdefined in relation to each other in the stored sequence of broadcastcontent, and wherein selecting the reference section and the testsection from the stored sequence of broadcast content comprisesselecting from the stored sequence of broadcast content a first timesection as the test section and selecting from the same stored sequenceof broadcast content a second time section, ranging from an end point ofthe test section, as the reference section; extracting fingerprintsrespectively from the selected reference section and from the selectedtest section, using one or more fingerprint extraction methods;comparing the extracted fingerprints from the test section with theextracted fingerprints from the reference section to perform matchingbetween the compared fingerprints; determining advertisement segmentsfrom the test section based on results of the matching; storing segmentinformation about the determined advertisement segments in anadvertisement database; and changing the reference section and the testsection.
 11. The method of claim 10, wherein selecting the first timesection as the test section comprises selecting as the first timesection a time section ranging from a most recent storage point of thestored sequence of broadcast content.
 12. The method of claim 10,wherein extracting fingerprints respectively from the selected referencesection and from the selected test section comprises partitioning eachof the reference section and the test section into unit sections havinga preset time length, and extracting a fingerprint from each unitsection using a fingerprint extraction method, and wherein comparing theextracted fingerprints from the test section with the extractedfingerprints from the reference section comprises, for each unit sectionof the test section, comparing a fingerprint extracted from the unitsection of the test section with fingerprints extracted from all unitsections of the reference section.
 13. The method claim 12, whereinstart points of the unit sections are spaced apart from each other by afirst time length, and wherein the first time length between the startpoints of the unit sections is shorter than the preset time length ofeach unit section.
 14. The method of claim 12, wherein determiningadvertisement segments from the test section based on results of thecomparing comprises determining advertisement segments as continuousunit sections of the test section that match unit sections of thereference section.
 15. The method of claim 10, wherein storing segmentinformation about the determined advertisement segments in anadvertisement database comprises storing in the advertisement database(i) one or more fingerprints from the determined advertisement segmentsand (ii) pieces of time information about the advertisement segments.16. The method of claim 10, wherein the selected test section is a morerecent time segment than the selected reference section in the sequenceof content.
 17. A method for advertisement detection based onfingerprints, the method comprising: storing broadcast content in realtime, wherein the stored broadcast content defines a sequence of contentover time; selecting a reference section and a test section from thestored broadcast content, wherein the selected test section and theselected reference section are respective time sections defined inrelation to each other in the sequence of content; extractingfingerprints respectively from the selected reference section and fromthe selected test section, using one or more fingerprint extractionmethods; comparing the extracted fingerprints from the test section withthe extracted fingerprints from the reference section to performmatching between the compared fingerprints; determining advertisementsegments from the test section based on results of the matching; storingsegment information about the determined advertisement segments in anadvertisement database; and for each advertisement segment, (a)partitioning into respective unit sections having a preset time lengthboth the advertisement segment and a section corresponding to theadvertisement segment in the reference section, and extractingfingerprints from the respective unit sections, (b) for each respectiveunit section of the advertisement segment, comparing a fingerprintextracted from the respective unit section with fingerprints extractedfrom all respective unit sections corresponding to the advertisementsegment in the reference section, and (c) determining continuousrespective unit sections of the advertisement segment that matchrespective unit sections corresponding to the advertisement segment inthe reference section, to be the advertisement segment.
 18. The methodof claim 17, wherein selecting the reference section and the testsection from the stored broadcast content comprises selecting apredetermined time section, ranging from a most recent storage timepoint, as the test section from the broadcast content and selecting apredetermined time section, ranging from an end point of the testsection, as the reference section.
 19. The method of claim 17, whereinstoring segment information about the determined advertisement segmentsin an advertisement database comprises storing in the advertisementdatabase (i) one or more fingerprints from the determined advertisementsegments and (ii) pieces of time information about the advertisementsegments.
 20. The method of claim 17, wherein the selected test sectionis a more recent time segment than the selected reference section in thesequence of content.